Geospatial Solutions » Geospatial Informationhttp://www10.giscafe.com/blogs/intermap
Just another GIS Blogs siteSun, 01 Dec 2013 17:05:14 +0000en-UShourly1http://wordpress.org/?v=4.1.1Precise positinghttp://www10.giscafe.com/blogs/intermap/2013/11/26/129/
http://www10.giscafe.com/blogs/intermap/2013/11/26/129/#commentsTue, 26 Nov 2013 18:44:49 +0000http://www10.giscafe.com/blogs/intermap/?p=129Precise positing – the ability to know your location from a latitude – longitude, or X-Y location, on the earth and how high above mean sea level your feet are firmly planted on the ground to within centimeters. Is this type of information becoming a wave of the future or am I just a geek about it? When I go to the gym in the morning, I am strapped with my fitbit and my Polar Heart Rate monitor which provide me with information about my speed, distance, x-y-z location, and heart rate while I train. Not to mention, providing me with an avenue to publish my activity via social media to participate in competitions with friends. J This type of information can be plotted on Google Earth to see where I have traversed, although, sadly enough when I workout at the gym my traverse is a “dot” as I barely change in x and y or z (height) for that matter, when on a treadmill. On the other hand, when I am outside, my walk changes in all three dimensions which can be displayed quite nicely in Google.

Such information has been made possible with the advent of GNSS (Global Navigation Satellite System) which started with the launch of the U. S. Department of Defence Global Positioning System (GPS) in the late 1970’s. Early applications of GNSS were adapted by the military and in the fields of survey and mapping. Today, the GNSS user community has branched out to include construction, engineering, agriculture, natural resources, and of course gym enthusiasts. How precise are we getting?

My Polar device is a little less precise making my x-y and z location to within a meter or so, however, hand held devices are becoming more and more accurate as GPS giants like Trimble have jumped into creating iPhone and Android operating system smart-phone apps. For example, Trimble Outdoors Navigator Hiking GPS App is available free for your iPhone or Android. It takes advantage of your smart phone’s high-resolution color touch-screens, built-in GPS sensors, and cameras which make them a natural platform for maps, trail guides, photo taking and sharing, social media sharing, mileage and travel logs, and tracking your activity route. The Trimble Outdoors Navigator app has a robust feature set for hikers including fully integrated GPS, five different map types, including streets, aerial, hybrid, topographic, and terrain, plus the ability to download and store maps on the phone, so you can use maps when out of cell phone/data range allowing for accuracies much better than a meter.

To satisfy geeks like myself, the Navigator app is also rich in other technical features that include a digital compass showing magnetic north and true north, the ability to mark, store, and describe waypoints, stored tracks, and the ability to match your latitude/longitude or UTM coordinates to your paper map or GPS device.

How are you using precise positioning in your everyday like? What type of accuracies are you achieving?

]]>http://www10.giscafe.com/blogs/intermap/2013/11/26/129/feed/1Careers in Remote Sensing Part IIhttp://www10.giscafe.com/blogs/intermap/2013/11/15/careers-in-remote-sensing-part-ii/
http://www10.giscafe.com/blogs/intermap/2013/11/15/careers-in-remote-sensing-part-ii/#commentsFri, 15 Nov 2013 19:17:34 +0000http://www10.giscafe.com/blogs/intermap/?p=126On August 20th I posted a blog on a distinguished Intermap employee “Mr. Robert Crawford” who has been in the remote sensing business for nearly four decades. The blog had a snipped of a newspaper article from “CORPUS CHRISTI CALLER dating back to February 18, 1977.

Today I clip another part of that newspaper article that speaks to the remote sensing tasks that Bob was working on back in 1977! All of these applications are still important in Remote Sensing today, however, there has been quite a few changes moving from paper/analog methods to three, four and even five dimensional digital remote sensing techniques are deployed to solve the same issues Bob faced in 1977.

I will be participating in a webinar on Remote Sensing careers hosted by The Geological Remote Sensing Group (https://www.grsg.org.uk/) for North America. Please join us to hear about three difference career paths in Remote Sensing

]]>http://www10.giscafe.com/blogs/intermap/2013/11/15/careers-in-remote-sensing-part-ii/feed/0Accuracy of Flood Modeling?http://www10.giscafe.com/blogs/intermap/2013/11/12/accuracy-of-flood-modeling/
http://www10.giscafe.com/blogs/intermap/2013/11/12/accuracy-of-flood-modeling/#commentsTue, 12 Nov 2013 18:27:23 +0000http://www10.giscafe.com/blogs/intermap/?p=122Flood inundation models provide predictions of the depth and extent of a potential flood. This information is then used in the assessment of risk to life and property in the floodplain (e.g. creation of hazard and risk flood maps), and to develop mitigation and restoration strategies. We have seen over the past decade significant advances in flood inundation modeling due to advances in hydrological modeling software coupled with the availability of more accurate elevation data. But how is the accuracy flood hazard and risk maps established?

The data requirements for any flood inundation model start with a digital elevation model that represents the elevation of bare ground features and is often referred to as a digital terrain model or a DTM. The vertical accuracy of DTMs is often used as a data requirement for use in flood hazard and flood risk assessments. Different nations have different accuracy requirements for DTMs to be used in flood modeling.

Using guidelines put forth by FEMA, Intermap Technologies® has been able to establish the regions where the NEXTMap® data meet FEMA requirements as a DTM dataset to be used for floodplain mapping across continental USA. NEXTMap DTMs satisfies FEMA’s Risk MAP requirements for the majority of the United States lower 48 states. In accord with FEMA’s standards for LiDAR and other high-quality digital topography datasets, the NEXTMap DTM data meets the decile requirements for accuracy and density for the low and medium decile watersheds, as illustrated in this map.

The NEXTMap DTM is hydro-enforced to ensure structures over water bodies (such as bridges) are removed, water surfaces are flat, and watercourses flow downstream. These DTMs are then used to derive:

county or statewide watersheds

flood risk areas surrounding critical floodplains

isolated areas that largely have low flood risk, but may have population clusters with significant risks

other areas in critical need of map updates where funding is limited

But what are the standards for elevation data used in the creation of flood maps in other parts of the world? How do we properly validate flood maps in other parts of the globe?

]]>http://www10.giscafe.com/blogs/intermap/2013/11/12/accuracy-of-flood-modeling/feed/0Geospatial Data for Geological Applicationshttp://www10.giscafe.com/blogs/intermap/2013/10/29/geospatial-data-for-geological-applications/
http://www10.giscafe.com/blogs/intermap/2013/10/29/geospatial-data-for-geological-applications/#commentsTue, 29 Oct 2013 16:33:10 +0000http://www10.giscafe.com/blogs/intermap/?p=108Within many of the world’s natural resource rich countries, the mining industry faces a number of key challenges including, but not limited to: prospecting in uncharted land; managing the remote locations of new deposits; gathering multiple datasets to one environment, production delays due to adverse weather; understanding, managing, and averting risk impacts, and bringing supply to market. Moreover, geologists use a vast variety of geospatial datasets that typically include bedrock and surficial geological maps, airborne geophysical survey data, geochemistry of lake-sediment samples, mineral occurrence data, structural lineaments, fold axes and formation contacts, as well as base maps to get the answers they need. Integrating these disparate datasets into one environment is key in understanding natural resource potential, especially in remote locations.

In most cases, integrated databases provide important clues that lead to discoveries such as areas favorable for gold mineralization based on the distribution of known gold occurrences, or where to drill for oil. Such analysis comes much easier and provides more accurate results when using a geospatial database that integrates field data and digital geological geospatial data providing a basis for the use of interpolation methods based on many different types of analytical methods, like those presented by Spatial Energy (see link below for a webinar) and Virtalis and the British Geologic Survey (see them at the GSA conference – link below).

Such applications are able to handle multi-scale geological models contain three-dimensional, spatially referenced data, typically spanning at least six orders of magnitude from outcrop to regional scale, which help to quantify some types of uncertainty associated with subsurface interpretation, and the use of this uncertainty to evaluate the validity of competing interpretations. In other words, they provide geologists with the ability to see through bedrock to understand where the mineral potential is, so to speak. To learn more about geological applications using geospatial databases and 3D software, check out the GSA Conference and Spatial Energy’s webinar.

]]>http://www10.giscafe.com/blogs/intermap/2013/10/29/geospatial-data-for-geological-applications/feed/0Geospatial data saving the planet?http://www10.giscafe.com/blogs/intermap/2013/10/22/geospatial-data-saving-the-planet/
http://www10.giscafe.com/blogs/intermap/2013/10/22/geospatial-data-saving-the-planet/#commentsTue, 22 Oct 2013 17:02:56 +0000http://www10.giscafe.com/blogs/intermap/?p=101Perhaps a dramatic title for today’s blog, but an interesting article from the World Wildlife Fund that I read on Friday has been on my mind all weekend. The gist of the newsletter topic was to investigate how we can produce more with less water and pollution by working with 100 companies and just 15 raw materials (or commodities). If that tagline tweaked your interest, I bet Jason Clay’s speech on this topic would more than get you to where I was on Friday, thinking about this topic for a few days.

As we geospatial users become knee deep in geospatial data, the web, the cloud, and analytical tools for a host of geospatial applications, I wonder how we respond to the type of thought process Jason encourages. I believe that in order to contribute globally, where geospatial data is used to save the planet, you must get every part of the food chain involved, so that an idea can be sustained over long terms rather than one offs. How may we use geospatial data to provide a better, sustainable carbon footprint for all? How can we get everyone to work together to manage the planet with a sense of urgency? To help preserve the planet, we need work together to preserve biodiversity as a starting point. Jason identifies 15 commodities that are produced in bio-diversity rich geographic locations. He also indicates that the top 100 companies control 25% of the trade of all 15 commodities. By working with 100 companies to promote and accept sustainably-derived commodities (which means they will force or push producers to act sustainably) we can start the process of saving our planet.

One company, Cargill, has funded research about how to double global palm oil production without further deforestation in the next 20 years. This is an important move in the direction of sustainable palm oil production, which may provide a compelling example for other companies to follow. Using remotely sensed data (imagery and elevation data) we can help to identify where degraded land of slopes less than 10 degrees already exists, and begin oil palm plantations at those locations. I urge you to watch Jason’s video and start a dialogue on how we geospatial users can assist in achieving a sustainable planet by helping to promote sustainable production of these 15 commodities.

]]>http://www10.giscafe.com/blogs/intermap/2013/10/22/geospatial-data-saving-the-planet/feed/0SAR Imagery: Is there a way to focus it?http://www10.giscafe.com/blogs/intermap/2013/10/15/sar-imagery/
http://www10.giscafe.com/blogs/intermap/2013/10/15/sar-imagery/#commentsTue, 15 Oct 2013 16:25:33 +0000http://www10.giscafe.com/blogs/intermap/?p=96Synthetic aperture radar or SAR imagery can be challenging for non-radar geeks to figure out what exactly the SAR image is illustrating. Of course our eyes have little trouble understanding aerial photo images primarily because the cameras used to collected photos operate at similar wavelengths (located in the visible portion of the electromagnetic (EM) spectrum) to our eyes. SAR sensors on the other hand, operate in the microwave portions of the EM spectrum which is very different from how our eyes see.

A SAR or radar image is formed from the mapping of observed radar signals reflected from the terrain and recorded by a radar sensor. For radar systems with digital image processing, like that of Intermap®’s or ASTRIUM’s radar systems, the SAR image consists of a file of digital numbers (DNs) assigned to spatial positions in a grid of pixels (picture elements). Each pixel represents the amount of EM energy recorded by the radar sensor over a known area and is denoted by the DN. See Figure 1.

Figure 1. Illustrates the relationship among a raster radar image, image pixels, and DNs. This illustration is comprised of a radar image (far left view of a residential area under construction), a close-up of a section of the radar image to illustrate the radar image pixels (middle image), and the DN for the corresponding image pixels (far right image).

Hopefully you can interpret this radar image using the content presented in my Radar interpretation blog published on September 3rd . But maybe if you had the advantage of requested a higher resolution SAR image you might notice that it seems as if you put on radar classes because the higher resolution image looks more in focus? Yes? Check out the different resolution images below in Figures 2 and 3 for yourself. In both cases, the left images were collected with 135 MHz (1.25 m pixel resolution) whereas the right images were collected with 270 MHz (0.625 m pixel resolution).

Two SAR images over the same area. Left Image: 1.25 m pixel resoltution; Right Image: 0.625 m pixel resolution

]]>http://www10.giscafe.com/blogs/intermap/2013/10/15/sar-imagery/feed/0Seeing through the treeshttp://www10.giscafe.com/blogs/intermap/2013/09/13/seeing-through-the-trees/
http://www10.giscafe.com/blogs/intermap/2013/09/13/seeing-through-the-trees/#commentsFri, 13 Sep 2013 18:32:29 +0000http://www10.giscafe.com/blogs/intermap/?p=37Successful mining exploration relies heavily on the accuracy of the geology map layer that depicts the spatial distribution of geologic units and structure. Often times, however, existing geologic maps vary in quality and accuracy due to differences in purpose of mapping, scale or level of details, inconsistency in nomenclatures, and types of map projection/registration. Conventional mapping methods of bringing existing geologic maps to the desired quality level or standard will entail a large amount of time and effort, and consequently will also drastically slow down mineral exploration. The creation of digital geology maps (map components: topography, structure, and lithology) from the desktop using interferometric syntehtic aperture radar (IFSAR or InSAR) provides a cost effective method, espeically in remote dense vegetated areas.

Surficial geology and inferred stratigraphy can be mapped using IFSAR derived elevation data (e.g. NEXTMap® DSM/DTM and ASTRIUM Tandem-X DSM) combined with SAR imagery (e.g. NEXTMap ORI, TerraSAR-X). Unconsolidated sediments are often manifested as topographic relief. Radar is sensitive to changes in moisture and roughness, which results in contrasting backscatter between different soil types and thus different vegetation cover. Topographic patterns displayed in perspective views of SAR DEM data, represented as shaded relief topography, make geologic features “pop” out, allowing for 1:10,000 to 100,000 scales regional and reconnaissance geologic mapping. Contour generation from the IFSAR DEMs, coupled with the rich texture offered in the SAR imagery, provide a medium to map drainage patterns. The drainage patterns, SAR texture, and geologic structure yield important clues about lithology to round out the last component of a geologic map. These geologic geospatial layers feed reconnaissance mapping and mineral exploration, without stepping into the field.

]]>http://www10.giscafe.com/blogs/intermap/2013/09/13/seeing-through-the-trees/feed/0Radar Image Interpretationhttp://www10.giscafe.com/blogs/intermap/2013/09/03/radar-image-interpretation/
http://www10.giscafe.com/blogs/intermap/2013/09/03/radar-image-interpretation/#commentsTue, 03 Sep 2013 16:13:37 +0000http://www10.giscafe.com/blogs/intermap/?p=20Synthetic aperture radar (SAR) sensors “see” the ground in a different way from optical sensors such as SPOT, aerial cameras, or the human eye; therefore, radar images have certain characteristics that are fundamentally different from those in images collected by optical sensors. The key then to understanding and interpreting radar images lies in the answer to this question: What happens to the electromagnetic energy in a radar pulse as it meets the terrain being imaged, interacts with the terrain, is recorded by the radar sensor, and subsequently is processed to generate a radar image? Answering this question is not easy. However, with the resolution of SAR sensors are getting better and better, details provided in, for example a 50 cm pixel, help our eyes to discern topographic features more readily than ever before.

Pictured here is a 50 cm pixel resolution NEXTMap® orthorectified radar image for a typical suburban development in North America (Colorado, U.S.A.). The high resolution imagery provides great detail about the structure of the residential features which in turn allows your eyes to quickly conclude that this represents a residential area. Taking a closer look at the SAR or radar image will demonstrate why it is important to understand how a SAR signal interacts with the residential features being imaged.

Recall that the gray levels of a radar image are related to the relative strength of the microwave energy backscattered by the terrain being imaged. Tightly knitted homes appear on the radar image as square-shaped, bright image toned features that are evenly spaced. The bright tones are the result of much of the original SAR signal making its way back to signal recorder. The primary and secondary roads, on the other hand, appear dark in image tone, smooth in texture, and exhibit a uniform, linear shape. The roads are dark in image tone because much of the transmitted SAR signal is reflected away from the signal recorded. The larger objects with an overall bright image tone in the center top and center bottom portion of the image are most likely schools, due to their proximity to the homes and because they are large complexes surrounded by sports facilities such as tennis courts, baseball fields, or tracks. We can also see that the intensity of the radar signal is affected by radar look direction where brighter images tones will come from those city blocks oriented parallel and/or perpendicular to the radar illumination (houses along the streets oriented north–south). In contrast, those streets oriented oblique to the radar look direction appear light to medium gray image tone. Can you tell what the radar look direction is? A short lesson on SAR image interpretation to hopefully spark a conversation about what your thoughts are on the skill set required to interpret high resolution SAR images.

]]>http://www10.giscafe.com/blogs/intermap/2013/09/03/radar-image-interpretation/feed/0A career in mapping stands the test of timehttp://www10.giscafe.com/blogs/intermap/2013/08/20/4-decades-mapping-careers/
http://www10.giscafe.com/blogs/intermap/2013/08/20/4-decades-mapping-careers/#commentsTue, 20 Aug 2013 16:25:39 +0000http://www10.giscafe.com/blogs/intermap/?p=15A career in remote sensing and GIS exists in every imaginable discipline, from environmental science to commercial businesses and much more. Such a career path has a wide range of opportunities available to let you combine your passions or interests with GIS and or remote sensing for a satisfying and successful career. Intermap’s very own Senior Project Manager, who keeps us on track with our large mapping projects where we are currently mapping the diverse landscapes in the Philippine’s and Alaska, has been in the mapping industry for the past four decades.

Today, Bob Crawford is still bringing a tremendous value to the mapping or as we say today, the geospatial community, offering his years of expertise to help us be more efficient, cost effective, while still maintaining quality and great customer service! Take a look back at a few highlights in remote sensing mapping taken from Bob’s four decades in the industry:

1977 – Specialized in high altitude Lear Jet photography for the U.S.G.S. orthophoto quad mapping program (NHAP)1980s – Photogrammetric Digital conversion and GIS software development for the U.S. Army Corps of Engineers military bases in West Germany